1. Field of the Invention
The present invention relates to a method for producing a thiolane skeleton-type glycoconjugate and the thiolane skeleton-type glycoconjugate.
2. Description of the Related Art
It is known that thionucleoside obtained by substituting an oxygen atom with a sulfur atom exhibits an antiviral activity or an antitumor activity.
For example, it is known that 1-(2-deoxy-2-fluoro-4-thio-β-D-arabinofuranosyl) cytosine has an excellent antitumor activity and is useful as a tumor therapeutic agent (refer to WO1997/038001A).
Therefore, studies on routes for synthesizing thionucleoside and synthetic intermediates thereof have been actively performed.
Among these, reactions for forming a thiolane ring are also widely studied and proposed (for example, refer to U.S. Pat. Nos. 3,243,425A, 7,148,223B, JP4719356B, WO1999/043690A, JP2007-514643A, JP4202327B, and JP2006-335737A).
On the other hand, although not a glycoconjugate, synthesis of a benzotetrahydrothiophene ring (refer to JP2006-335737A) and a synthesis reaction of iminosugar (refer to CN1010585855A and Synlett, 2010, No 3, p. 488-492) are also known.